1. Technical Field of Invention
This invention relates to clamps for forge dies and more specifically for an improved clamp ring having an integrated pre-heater.
2. Description of Prior Art
Forge dies are heated for two basic reasons. First is the material flow during the forge operation. The material being forged will flow better with a heated die, especially aluminum. If one forges aluminum, for example, without heating the dies you are more likely to get a non-fill condition, which means that the forged part will be incomplete in the corners, leading to scrapped parts. The second reason for heating the dies is that they will last longer if they are ran at an elevated temperature; cold dies will crack faster than a die that is heated.
Traditionally, dies were clamped to the forge press and heated using one of two different methods. In the first method, dies were clamped to the forge press with a clamp ring and then a separate heating ring was placed around the die. The heating ring was then connected to a propane gas supply and the resulting flames heated the die. In the second prior art method, two torches on either sides of the die acted as a heat source. Both of these heating methods make it difficult to precisely control the die temperature and the temperature must be controlled with a certain range, particularly for aluminum. If the dies are too cold you will get a non-fill as discussed above. If the dies are too hot then the metal will stick to the die surface as the forging process takes place; also causing parts to be scrapped due to a smeared appearance on the surface of the finished part.
In addition to requiring at least two separate components, such prior art methods are also inefficient because the flames of the heating elements were up to five (5) inches away form the forge die surface. Another drawback of the first prior art method is that it is difficult to hold the die heating ring in place while operating the forge press. As a result, the ring can shift position as the press was activated, causing the ring to be crushed and putting the operator in a dangerous situation as well as contributing to costly maintenance fees to repair broken dies. With the second “torch” method, the dies were not heated evenly, causing stress in the die that lead to premature failure.